Clamping means



Nov. 25, 1930. E; E. VON TELL CLANPING MEANS Filed Sept.

.Iilliiiiiililliilb INYENTOL 7 fil 7mg Patented Nov. 25, 1930 I EDWARDnLrAs voN TELL, F CtOTTENBbRG, swEDEn oLAiurINGi MEANS Application filed September is, iegaiseriai110,393,499,and in Sweden July s, m9.

This invention re'latesto ineans for securmg a movable ObJBOl] nposltion byclamplng it against a stationary member. 7 Such a clampingaction can be util zed for a plurality of purposes as for instance whensecur ng a 7 work pieceto the chuck oriface' of :a lathe,

. or the haul rope of a-shipto the bittspor a sliding window of anautocar orrailway car or the like. Especially I prefer to use myimproved clamping meansto secure thetarpaulin over a ships'hatch cover.y a

One purpose of the improved clamping device istoprovidea substitute forany loose a wooden wedge or similarmeinbers which hitherto arefrequentlyused for such clamping effect, and which loose wedges arerather apt to be laid aside and lost. V V i J Another object of myinvention is to provide a clamping means which always is ready 2e foruseand which'can be operatedby-nieans ofsimple implements, butneverthelesswith a high degreeofeffectivity.

A further object of my clamping device withaldouble safety in itsclamping effect, viz. on the one hand the lockclamping member and: theobject to; be

clamped, and on the otherhand the locking effect caused by the frictionbetween the member.

In order to obtain the purposes mentioned above I havedesignedmyclamping device in the shape of an eccentric pivotablenpon a Vpivot and provided with alujg or-prong'disposed in such a relation tothe pivot that a nut, so that-the nut will be; moved along the a screwbolt pivot simultaneously,with theror tatingof theeccentrifcby ineansofthescrew trio.

ingefiect caused; by the friction between-the clamping member and the.support for'said,

down hanging edges of thetarpaulin 5 are tightened tothe side of the'coaming, and'the tarpaulin securedthereto by a clamping bar 6'whichiasfusual runs along the side offthe'i jcoaming, such a .clanipingbar 6 being procoaming.

wrench lever operating: the lug on the eccen l The combined or. doublean efltect 0b tamed by locking the eccentric whenfclampmg the object tobe treated, increases consid' erably the usefulness of the device as itwill prevent its noni'ntentional releasing even in centric, and withdot-andsdash lines when i changed on the nut so as to come freefrom thea lug on the. eccentric when turning the nut Fig. 3shows on aminor scalein elevation a portion of the latchcoaming viewed from outside, andprovided with the improved Z0,

clamping device, but with hatch coverand] L u tarpaulinremoved,invention is a Fig. 4: onithe same reduced scale as Fig. 3, asectional-plan View of the parts shown in said figure, and p j I i Fig.5 in 'section ona larger scale than Figs. land 2 the upper portion ofthe pivot when designed asascrewbolt; Q Inthe drawing-1 designatestheship s deck and 2 the hatch coaming whichasusual on largehatches isreinforced a big bulb iron 3. The'hatch cover is designated with 4, andX the tarpaulin which is spread thereabove in theyusual way isdesignated. wars. The

vided, along. 1 each :of the -four, sides a of "the,

v In accordance withthis invention leach,

clamping bar 6 is pressed against the airpaulin 5 am dconsequently thecorresponding edge of the tarpaulin against the side. of the hatchcoaming '2 by means ll of an eccentrio 7 which'isrotatableabout-ayvertical pivot 8 projecting upwardsfrom thehorizontal flange ofthe bulb iron 3, whereby the pivot 8 preferably isinserted through: a 'hol in said flange and stopped against theunderside thereof by a head 12. Figs. 3 and 1 show a plurality of sucheccentrics disposed along the sides of the hatch coaming on suchdistances as are necessary to suit the sizes of the clamping bar 6exactly as is the case with the wooden wedges hitherto used for the samepurposes.

According to Fig. 1 the eccentric is composed of three parts viz. onecentre part 9 which is the real clamping part, and two side parts 10 and11 which serve to hold the part 9 between them. The centre part 9 may beconstructed of a'inaterial which does not unduly wear and tear theclamping bar 6 but acts with necessary friction so as to secure the barin clamped position. As such a material, can be utilized some hard wood,forin'stance beech, or any of the composite materials which are used inwheel brakes, autocar couplings or similar devices. The side parts 10,11 are made of iron or other metals and serve also as washers for thescrew bolts which keep the parts 9, 10, 11 assembled without preventingtheir dismounting for renewing of the softer centre part 9. Theseassembling screw bolts comprise the pivot 8 which is designed as a screwbolt with head 12 and nut 13, and a screw bolt 14: arranged at somedistance from the pivot 8, and provided with head 17 and nut 16. Tofacilitate the rotating of the eccentric, a washer 18 may be providedbetween the eccentric and the bulb iron 3 so as to reduce the frictionbetween said parts.

The lower washer 11 of the eccentric ought to have a larger peripherythan that of the operative centre part 9, thereby constituting a bridgeor shoulder 19 that projects outside the operative surface of part 9,and serves as a support for the clamping bar 6 before the bar has beenclamped towards the hatch coaming. That will be clearly understood byFig. 1. Naturally, if so wanted, also the upper washer 10 can bedesigned in the similar way, thus forming a channel in which theclamping bar 6 will be more steadily secured.

When the tarpaulin is to be clamped between the bar 6 and the hatchcoaming 2, a wrench 15 is laid on the nut 13 which wrench is providedwith a tongue 20 projecting in the main direction of the wrench shaft 21but on the opposite side of the awe of the wrench. The wrench thenobtains the character of a double armed lever which when tightening theclamping bar 6 will be used as described in the following: The wrench isswung with the nut 13 until its tongue 20 contacts the nut 16 or theprojecting end of the bolt 14; a further swinging of wrench 15 now'willmake the eccentric 7 follow said motion on account of the wrench servingas a double armed lever pivoted around the bolt 8 and acting on lug orprong 16 or 14 of the eccentric by its short arm 20. The eccentric, as aconsequence, is pressed with the operative surface of the centre part 9against the clamping bar 6 which in its turn forces the down hangingedge of the tarpaulin tight against the hatch coaming 2. When saidturning of the eccentric 7 has gone on so far as the force applied tothe wrench shaft 21 is apt to clamp the tarpaulin between bar 6 andhatch coaming 2, the wrench 15 is removed off the nut 13 and shifted toanother position thereupon so that its tongue 20 comes free of the nut16 exemplified by the dot-and-dash lines in Fig. 2. \Vhen the wrench nowis swung in the same direction as before there is nothing which preventssuch a movement, and as a consequence the nut 13 without influencing theabove mentioned position of the eccentric will be set on the bolt 8 somuch as is necessary to tighten the eccentric downwards against thesupporting bulb iron 3, thus locking the eccentric in its clampingposition and preventing its nonintentional releasing therefrom. Thetightening of the tarpaulin thus is given a double safety, viz. atfirst, the friction arising between the curved surface of eccentric 7and the clamping bar 6, and secondly, the friction between the undersideof eccentric 7 and the bulb iron 3.

To release the tarpaulin one has to repeat the above mentioned operationbut in opposite direction and order. At first the nut 13 is slackened upby means of the wrench 15 in such a position that its tongue 20 does notcoact with the nut 16 or bolt 14:, and thereafter the wrench 15 getsshifted on the nut 13 to a position in which its tongue 20 will operatethe nut 16 or bolt 14: on the reverse side in comparison with that onFig. 2, whereby a swinging of the wrench will cause the eccentrio 7 torelease its grip on the clamping bar 6.

When the wrench 15 is used simply as a lever with the tongue 20operating the bolt 14, the nut 13 serves for a hub of the lever by meansof which the lever will turn about the bolt 8 as a pivot. The singledifference in comparison with an ordinary lever hub is, that the latterone will turn around a plainly cylindrical pin while the nut 13 duringits rotating slides along the threads of the screw threaded bolt 8, butthis difference executes an increased friction between hub and pivotaccording to the pressure between nut and bolt threads. Therefore it isnecessary to provide for a good lubricating in order to preventexcessive loss of forces. For that purpose the nut 13 is provided withan automatic lubricating device shown in F ig. 5. The end of the bolt 8has a central axial bore 22 which is screw threaded and closed by ascrew plug 23 that can be screwed out and in by means of a wrench or ascrew driver. The axial bore 22 terminates in one or more radial bores24 which terminate in the outer surface of the bolt 8 within the rangeof its threaded fcommon lever. By thisarrangement, however, the-abovement oned advantage of the portionth-atis'in assessments nut 13 whenoperative. If-the cavity in the bolt end com-posed bythe central-bore-21and the radial bore. or; bores 24: is filled with a lubricating grease,and the plug 23 is screwed inwards, thegrease will be forced out throughthe radial bore or bores 24fon the cooperating threads of bolt 8 and nut13 thus actingjinthesame way as a usual Staufi'er compression grease cupalways to keep the cooperating rubbinigsurfaces of nut and bolt in athoroughly lubricated condition. V

In its details my 'nvention can be varied in many ways withoutinterfering with its (material points. For instance the pivot 8 does notnecessarily have the-shape'oit' a screw bolt but can be a plain'pin ofthe usualtype whereby the wrenchlo will be replaced by a double'lockingeffect will be lost; Also the eccentric 7 does notnecessarily becomposed of different parts such as the centre part 9 and thetwo outerwashers 10, 11 butcan be made of a solid piece in which case theaseinblingbolt 14 can be dispensed with and replaced by a lug or prongformed in any suitable way and projecting from the top side of theeccentrio 7 so as to suit the cooperation with the a tongue 20. Furtherit is immaterial that the bolt 14 or its substitute be disposed on sucha side of the pivot 8: that the lever 15 must 7 t have thecharacter of adouble armed lever butit can be positioned on the opposite side of thepivot to cooperate with the shaft2l i proper. Thus the wrench will actas a single armed lever. If the pivot has the aforesaid character of ascrew bolt such a single armed lever may be replaced by a common wrenchwhich, of course, will reduce the installation costs butthe need offorce will be increased when operating the device, and hence I pre} ferto use a double. armed lever just as de scribed above." Furthermodifications in the design of the invention maybe undertakenin dueconformity with its various applications,

and can be clearly understood by everybody skilled in the art withoutneed to illustrate or describe them here.

Having thus particularly described'and' ascertained my improved clampingdevice and how it is to be performed, what-I claim new and wanttoprotect by Letters Patent 1s r a 1. A mechanical clamping devicecomprising a stationary ,base member, a pivot rigidly connected to saidbase member somewhat remote therefrom, an object provided to be clampedto said base member, an eccentric rotatable about said pivot so as to beswung against said object to clamp same against the base member, a lugon said eccentric spaced from said pivot, a lever provided to turn aboutsaid pivot, and to cooperate at some distance from its turning pointwith saidlug object against-the base member.

on the eccentric 'so as to forcibly turn the eccentric to clamp saidobject against the "base member. it

' 2. A mechanicalclamping device comprising a stationary base member, apivot rigidly connected to said basemember somewhat remotetherefroim-saidjpivot having the character of a screw'bolt with nut, anobject provided to be cjlamped to'said base member, aneccentriclrotatable aboutisaid screw bolt pivot,-so asflto be swungagainst said object to clamp same against the base rhembenfa'lug on saideccentric spaced fromxsaid pivot,-'a wrench provided to coact with saidnut so as to turn the nutlabout the screw bolt, thereby adaptedztocooperate at some distance from its turning point with saidlug on theeccen trio so as to forcibly turn the eccentrict td clamp said objectagainst the base member. 3; A inechanicaholamping.devicecomprise ing astationarybase member, a pivot rigidly connected to said base membersomewhat re mote therefrom, an object provided to be clamped to saidbase member, an eccentric ro; tatable about said" pivot so as to beswung against said object to clamp same against the base member, saideccentric composedby: an

operative centre portion of (some softer material and two metal sidewashers, said-pore" one side washer forming a lug disposed somewhatremote from the turning point of thesecentric, a lever provided to turnabout said pivot, and to cooperate at some distance from centric-so asto forcibly'turn the eccentric to clamp saidobject against the basemember.

tions assembled by a. throughgoing screw 9 bolt, the end ofwhichprojecting above the,

its turningupointwith: said lug onxthe ec- V 4:. A mechanical clampingdevice Tcomprisinga stationarybase member, apivot rigidly connected to.said base membersomewhat re-: mote-therefrom, said plvot havlngthecharacter of a screwbolt with nut,an object pjrovidedto be clampedto. said basesmembenan eccentric rotatable about said screw bolt pivot,so as to be swung against said object to'clamp same 'againstthebasemember, said eccentric composed byan, operative centre portion of somesofter material and two metal side washers, said portions assembled by athroughgoing screw rbolt, the. end of which projects above, theone sidewasher forming a lug disposedsomewhat remote from the clamped to saidbasemember, aneccen tric 1'0- to clamp said g V tatable about said pivotso as to be swung against said object to clamp same against the basemember, said eccentric composed by an operative centre portion of somesofter material and two metal side washers, said washers projectingoutwards of said operative centre portion thereby forming a bridge forthe support of the object to be treated.

6. A mechanical clamping device comprising a stationary base member, apivot rigidly connected to said base member somewhat remote therefrom,said pivot having the character of a screw bolt with nut, an object provided to be clamped to said base member, an eccentric rotatable aboutsaid screw bolt pivot, so as to be swung against said object to clampsame against the base member, a lug on said eccentric spaced from saidpivot, a wrench provided to coact with said nut so as to turn the nutabout the screw bolt, thereby adapted to cooperate at some distance fromits turning point with said lug on the eccentric so as to forcibly turnthe eccentric to clamp said object against the base member, said screwbolt pivot having a central bore in the screw threaded end which bore isscrew threaded and provided with a screw plug and terminates in one ormore radial bores which terminates or terminate on the threaded surfaceof the bolt within the range of the nut of the bolt when operative, saidcentral bore and radial bore or bores forming a cavity to be filled witha lubricant grease that by means of said screw plug can be forced out tothe threads of the bolt so as to oil them when in cooperation with thenut such as can be done with a common compression grease cup.

7. A ships hatch coaming, clamping bars along said hatch coamingprovided to tighten a tarpaulin against said coaming, pivots rigidlysecured along said coaming somewhat remote therefrom and convenientlyspaced from each other, eccentrics pivotable about said pivots so as totighten the tarpaulin against said hatch coaming and lugs on saideccentrics cooperating with levers pivotable about same pivots as theeccentrics to clamp the tarpaulin against the hatch coaming.

8. A mechanical clamping device comprising a stationary base'member, apivot rigidly connected to said base member somewhat remote therefrom,said pivot having the character of a screw bolt with nut, an objectprovided to be clamped to said base member, an eccentric rotatable aboutsaid screw bolt pivot, so as to be swung against said object to clampsame against the base member, a lug on said eccentric spaced from saidpivot, a wrench provided to coact with said nut so as to turn the nutabout the screw bolt, thereby adapted to cooperate at some distance fromits turning point with said lug on the eccentric so as to forcibly turnthe eccentric to clamp said object against the base member, said wrenchon the side of its jaws opposite to that of the shaft provided with atongue adapted to cooperate with the lug on the eccentric whentightening or slacking up same, the shape of said tongue being such thatthe tongue comes out of contact with said lugs, if the wrench getsshifted on its nut whereby the nut can be tightened without turning theeccentric.

In testimony whereof I have aflixed my signature.

EDWARD ELIAS VON TELL.

